Airbags and airbag systems have been known and used for decades and have been credited with saving many lives and preventing many injuries. Airbag systems are used to deploy an airbag during a crash into a vehicle interior so that the vehicle occupant will impact the deployed airbag rather than the harder surface(s) of the vehicle interior.
Airbag systems generally include an inflator. An inflator is a device that is designed to produce and/or channel a quantity of inflation gas into the airbag during the deployment process. This influx of gas into the airbag inflates and deploys the airbag into the proper position. A variety of different inflators are known in the industry.
One type of known inflator is the so-called “hybrid” inflator. Hybrid inflators include a quantity of stored gas along with a pyrotechnic gas generant that is combusted to produce additional inflation gas necessary to deploy the airbag. Accordingly, hybrid inflators generally include the quantity of gas generant housed within a housing that is contained in a pressure vessel.
Hybrid inflators deliver large quantities of inflation gas very quickly—i.e., within a few milliseconds. The pressure within a hybrid inflator may increase very rapidly due to the combustion of the gas generant. This increase in the pressure of the inflator corresponds with a certain initial rate of gas delivery to the airbag. This is referred to as the “onset” rate. In some situations, it may be desirable to lower the onset rate of the airbag used with a hybrid inflator. Such lowering of the onset rate will deploy the airbag at a slower velocity and may be beneficial if, for example, the occupant is “out-of-position.” Further, if the onset is decreased, the load acting on the airbag module would also decrease, thereby reducing the necessity and cost of using materials that can withstand extreme pressures.
Accordingly, the present embodiments relate to a new type of inflator that reduces the onset rate of a hybrid inflator.